CXCL8 and cognitive disorder: Daytime changes were positively correlated with IL-2 (r = 0.462, P = 0.030), IL-6 (r = 0.516, P = 0.017), and IL-8 (r = 0.462, P = 0.030) levels, and there was a positive correlation between cognitive disorder scores and IL-6 levels (r = 0.492, P = 0.023).